Method of manufacturing alkyl esters



Dec. 25 1923.

H. F. WILLKIE METHOD OF MANUFACTURING ALKYL 'ESTERS Filed Dec. 29. 1921 INVENTOR A TTORNE YS silent Dec. 5, E92.

car it LLKIE, F BALTIMORE, MYL

H ASSIGNOR, TO U. h. UST:

ALCOHOL (30., A CORPORATION OF WEST VIRGINIA.

METHOD OF MANUFACTURING ALKYL ESTEfi Application filed December 29, 1921. Serial Ito. 525358,

To all whom it may concern:

Be it known that I, HERMAN F. WILLKm, a citizen of the United States, a resident of Baltimore, State of Maryland, have ina vented a certain new and useful Method of Manufacturing Alkyl Esters, of which the following is a specification.

This invention relate to a method of parts of the apparatus connected to the reaction vessel.

The process may he conducted in various forms of apparatus but for the sake of a at specific embodiment the following apparatus will he described The figure of the drawing illustrates a simple type ofapparatus' for carrying out the process of this invention.

In said figure is shown a still 1 connected to a rectification column 2 which is filled with fragments of inert material such as glam beads. An electric heater 3 i suplied with a tube 4: for the admission of ydrochloric acid vapors and with a tube 5 connected to the column 2. A. thermometer d is also inserted into the electric heater 3. The electric heater which is heated by a suitable current of electricity passing through resistance coils 7 contains frag ments and particle of coke impre nated with a catalyst such as zinc chloride ior example. A tube 8 leads therefrom to a partial condenser 9 provided with a siphon 10 densed and also provided with a condenser 11 cooled by a chamber 12 into which water or. other cooling medium flows through a pipe 13 and leaves by a pipe 142. The siphon 10 leads hack to the flask 1 wherein the mixture of alcohol and water is rectified in order to provide approximately 95% alcohol for the interaction chamber 3. The condenser 11 is connected by apipe or tube 15 for removing the water and alcohol conto a wash bottle 16 containing: water and there are two other wash bottles 18 and 20 connected by lpipes '17 and 19 respectively and respective y filled with sodium hydroxide solution comprisin 10 parts by weight of sod um hydroxide d issolved in 100 parts by weight of water, and concentrated sulp uricacid having a strength'of over preferably over The strength of the sodmm hydroxide may vary considerably from a 10% solution. The pipe 21 leads from the bottle 20 to a condenser for condensing the product formed.-

In the operation of this apparatus alcohol is distilled from the rectifier 2 while h drochloric acid vapors are led in throug the pipe 4 into the heater 3 where the interaction takes place in the presence of the catalyst such as zinc chloride contained in the articles of coke, which provides a large sur ace for the catalyst even in case the latter should at times fuse." The water formed during the interaction between the acid and alcohol is extracted by the catalyst or dehydrator but is almost immediately expelled again by reason of the high temperature prevailing which does not permit condensation. of the water. The latter together with the other gaseous "products passes out through the pipe 8 into the dash 9 wherein the water and alcohol are condensed and constantly siphoned 0d through the pipe 10 while the remaining gases pass up into condenser 11 where any remaining water vapor is condensed together with most of the uncornhined alcohol and acid. b

The ester passes out through the pipe 15 and is washed free of acid in the bottle 16, any traces oiacid remaining being eliminated in the hottle 18. The ester passes along through the pipe 19 and is dried in the bottle 20 after which it is in pure condition and may he led to any suitable condenser or other receiving means.

It is an advantage to keep the acid and alcohol separate until they arrive in the interaction zone for To this means the formation of esters is avoided. The temperatures in the electric heater 3 are preferably between and C. so as to. insure the expulsion of the water. Catalysts and dehydraters other than zinc chloride may he used but the latter is preferable. llt is advisable to maintain an excess of about 10% rot - the alcoholused. Thewashers 16, 18 and and led back continuously to the rectifier 2. It is desirable to keep the zinc chloride dry the production of. the

at all times durin ester since this wil ins'ure'the maximum yields. The latter under the best practlces of the process may run as high -as 85% of 20 may be dispensed with and the. product may be recovered byfractlonat-lon from the mixture of alcohol, acid and ester, WhlCll would be condensed in that event.

The process of this invention is of general application to cases where it is desired to prepare an ester or s1m1lar compound from an acid and an alcohol by elimination of one or more molecules'of water. Wherever several compounds may be condensed to form a new compound the process may find application by those skilled in the art, the process being obviously capable of variation to suit the peculiarities of particular starting materials. Compounds havin the OH group capable of union with the of another compound, may be operated upon by this process, for example the monohydr c alcohols. The polyhydric alcohols may 1n suitable cases be used. Among the compounds capable of detaching nascent H may be named the acids and acid anhydrides such as nitrlc acid and the nitrogen oxides, SU, and S0 phthalic anhydride, volatile alifatic and aromatic acids and their volatile anhydrides, and acetic acid and its anhydride. Anhydrides of thealcohols may also be combined with. the acids, for example ether, ethylene, propylene, and propyl ether. By the term acid in the claims it is intended to include the acid anhydrides and acid-like bodies capable of condensation with a hydroxy group, and by the term alcohol 1t is 1ntended to include the alcoholic anhydrides.

As many apparently widely different embodiments of this invention may be made without departing from the spirit thereof, it is to be understood that I do not intend to limit myself to the specific embodiment thereof except as indicated in the appended claims.

I claim:

1. The method of manufacturing alkyl esters comprising allowing an acid and an excess of an alcohol to interact in a gaseous state in the presence of a solid catalyst maintained at a temperature suflicient to drive off the water formed during the interaction.

2. The method of manufacturing alkyl esters comprising allowing an acid and an excess of an alcohol to interact in a gaseous state in the presence of a catalyst carried on an inert carrier, at a temperature above the vaporizing point of the water formed.

3. The method of manufacturing alkyl esters comprising allowing an acid and an eXfiQSS Ofa-n alcohol to interact in a gaseous state in the presence of a catalyst maintained at a temperature sufficient to drive ofi the water formed, condensing the excess of the .alcohol, and returning it to the process.

4. The method of manufacturing alkyl esters. comprising allowing an acid and an excess of an alcohol to interact in a gaseous state in the presence of a catalyst maintained at a temperature sufficient to drive off the water formed, condensing the water formed and the excess alcohol, rectifying the mixture, and returning the alcohol to the process for reuse. 1

5. The method of manufacturing alkyl esters comprising allowing an acid and an excess of an alcohol to interact in the gaseous state in the presence of a catalyst maintained at a temperature sufficient to drive off the water formed, and recovering the excess alcohol for reuse in the process.

6. The method of manufacturing alkyl esters comprising allowing an acid and an alcohol to interact in a gaseous state within an electric furnace containing particles of an inert carrier carrying a catalyst, and maintaining the furnace at a temperature suflicient to drive off the water formed.

7. The method of manufacturing alkyl esters comprisin excess of an alco 01 to interact in a gaseous state in the presence of a catalyst maintained at a temperature sufficient to drive off the water formed. i

8. The method of manufacturing alkyl esters comprising allowing an acid and an alcohol to interact in a gaseous state Within an electric furnace containing particles of coke impregnated with zinc chloride, and maintaining the furnace at a temperature sufliciently high to drive off the water formed during the interaction.

9. The method of manufacturing alkyl esters comprising allowing an acid and an excess of an alcohol to interact in a gaseous state within an electric furnace containing particles of coke carrying zinc chloride, maintaining the furnace at a temperature sufliciently high to drive off the water formed during the interaction, condensing the water and the excess alcohol, rectifying the mixture, and returning the alcohol to the process.

10. The method of manufacturing alkyl esters comprising allowing a halogen acid and a monohydric alcohol to interact in the presence of a solid catalyst maintained at a temperature sufiicient to drive off the water formed durihg the interaction.

11. The method of manufacturing alkyl esters comprising allowing a halogen acid and an excess of a mono ydric alcohol to interact in a gaseous state in the presence allowing an acid and an masses of a catalyst carried on an inert carrier, at a temperature above the vaporizing point of the water formed.

12. The method of manufacturing alkyl esters comprisin allowing a halogen acid and an excess of a monohydric alcohol to interact in a gaseous state in the presence of a catalyst malntained at a temperature suf- -ficient to drive off the water formed, conter formed.

14. The method of manufacturing alkyl esters comprising allowing a halogen acid and an excess of a monohydric alcohol to interact in a gaseous state within an electric furnace containing particles of coke carryat a temperature sufiiciently ing zinc chloride, maintaining the furnace igh to drive off the water formed during the interaction, condensing the water and the excess alcohol, rectifying the mixture, and returning the alcohol to the process.

15. The method of manufacturing ethyl chloride comprising allowing gaseous hydrochloric acid and an excess of gaseous ethyl alcohol to interact in the presence of a catalyst maintained at a temperature sufliciently high to drive off the water formed.

16. The method of manufacturing ethyl chloride comprising allowing gaseous hydrochloric acid and an excess of gaseous ethyl alcohol to interact in the presence of particles of coke impregnated with zinc chloride, and maintainin the latter at a temperature sufficiently big to drive off the water formed during the interaction.

In testimony that I claim the foregoing, I have hereunto set my hand this 15 day of December, 1921. HERMAN F. WILLKIE. 

